Method of making a heat exchanger



Aug. 16, l9b6 JACOBS 3,266,128

METHOD OF MAKING A HEAT EXCHANGER Original Filed May 16, 1961 M I 3 14 a A? 1, ll

/6- I! [z I! v [I [I INVENTOR. James (4 Jacobs I H13 ATTORNEY United States Patent 3,266,128 METHOD OF MAKING A HEAT EXCHANGER James W. Jacobs, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Original application May 16, 1961, Ser. No. 110,397, now Patent No. 3,202,211. Divided and this application Feb. 18, 1965, Ser. No. 433,748

1 Claim. (Cl. 29-1575) This application is a division of application Serial No. 110,397, filed May 16, 1961, now United States Patent Number 3,202,211.

This invention relates to refrigerating apparatus and more particularly to a heat exchanger and to the method of manufacturing heat exchangers for use in refrigerating systems and the like.

It is an object of this invention to provide a heat exchanger having fiuid conduits and integrally formed fins made from relatively flat sheet stock.

It is another object of this invention to form flanged tubular projections on relatively flat sheets, which projections abut and are bonded to complementary projections on adjacent flat sheets to form fluid conduits.

More specifically, it is an object of this invention to reduce the amount of metal drawing necessary to join the fin structures together to form a gas-tight fluid passageway.

These and further objects and advantages of the present invention Will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

FIGURE 1 is a fragmentary side elevational view with parts broken away showing a heat exchanger embodying my invention;

FIGURE 2 is an elevational view showing one of the sheets used in making the heat exchanger shown in FIG- URE 1; and

FIGURE 3 is a fragmentary sectional view taken substantially on line 3-3 of FIGURE 2.

Referring now to the drawing wherein a preferred embodiment of the invention has been shown, a heat exchange unit, generally designated by the reference numeral 10, is formed from a plurality of fiat sheets 12 which not only form the heat radiating fins but also form fluid passages.

As shown in the drawings, each of the flat sheets '12 is provided with a plurality of relatively large diameter tubular projections 14 which are integral with the sheet and extend in one direction from the sheet. Each of the relatively large tubular projections is provided with a relatively small diameter internal projection 16 which is joined to the relatively large diameter tubular projection 14 by means of a relatively flat surface 18. The relatively flat surfaces 18 on adjacent pairs of sheets 12 are bonded to one anoter as shown so as to form bonded joints 20 between adjacent sheets. The terminal ends of the relatively small diameter tubular projection 16 are provided with internal flanges 22 which are bonded together as shown to form bonded joints 24. By virtue of the above-described arrangement, a plurality of parallel fluid passages are formed which, in effect, have integrally formed heat radiating fins. The necessary number of return bend elements, such as the element 30, are pro- Patented August 16, 1966 vided for connecting the ends of adjacent fluid passages 26. Suitable inlet and outlet connectors, such as the connector 32, may be provided as shown. The elements 30 and 32 telescope into the fluid passages 26 as shown.

By virtue of the above-described construction, it will be obvious that the draw necessary to form the tubular portions 14 and the re-entrant portions 16 is not greater than the distance between two adjacent sheets. This is an important feature in the manufacture of heat exchangers as it greatly reduces the number of leaks resulting from tea-rs in the metal due to excessively long draws.

The sheets are preferably made of basic aluminum to which is bonded on each side thereof a lower melting temperature aluminum brazing or bonding material. The entire assembly is clamped together and dipped brazed in the presence of flux whereby all joints are simultaneously brazed in accordance with well known brazing procedures.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

A method for manufacturing a heat exchanger having a plurality of separate fin elements each having integral tube forming portions, comprising the steps of, reversely drawing an interior portion of a first fiat sheet to form a first large tubular projection extending from one side of the first sheet and to form a relatively smaller open-ended tubular projection integral with the first projection and arranged interiorly and concentrically of the first projection to extend past the opposite side of the first sheet, reversely drawing an interior portion of a second flat sheet to form a second large tubular projection extending from one side of the second sheet and to form a relatively smaller open-ended tubular projection integral with the second large tubular projection and arranged interiorly and concentrically of the second large tubular projection to extend past the opposite side of the second sheet, maintaining a continuous spaced relationship between the undeformed portions of the first and second sheets by aligning and bonding the first and second large tubular projections with one another in abutting relationship, and aligning and bonding the smaller tubular projections of said first and second sheets in abutting relationship with the smaller tubular projections of additional sheets of a configuration similar to said first and second sheets whereby a conduit is formed through said spaced apart sheets.

References Cited by the Examiner UNITED STATES PATENTS 1,731,575 10/ 1929 Hyde. 1,787,942 1/ 1931 Kalloch -181 1,954,638 4/1934 Loefller 165-130 XR 2,045,657 6/ 1936- Karmazin 165-151 2,959,402 11/ 1960 Edwards 165-182 FOREIGN PATENTS 77,985 8/ 1919 Austria.

6,541 1909 Great Britain. 371,605 4/1932 Great Britain. 672,7 09 5/ 1952 Great Britain.

JOHN F. CAMPBELL, Primary Examiner.

WHITMORE A. WILTZ, Examiner.

J. D. HOBART, Assistant Examiner. 

